* mu-store/index: better up-to-date check: see if message is in db already

mu-store-xapian: add mu_store_contains_message;
  mu_index: update the check

  we cannot just rely on the timestamp, because messages may be moved from
  elsewhere, e.g. from 'new' to 'cur'

src/mu-index.c

@@ -83,15 +83,30 @@ _insert_or_update_maybe (const char* fullpath, time_t filestamp,
 			 MuIndexCallbackData *data, gboolean *updated)
 { 
 	MuMsgGMime *msg;
-
+	
 	*updated = FALSE;
 
-	g_debug ("msg: %s (%u)", fullpath,(size_t)filestamp);
+	/* checks to determine if we need to (re)index this message */
+	do {
+		/* unconditionally reindex */
+		if (data->_reindex)
+			break;
+
+		/* it's not in the database yet */
+		if (!mu_store_contains_message (data->_xapian, fullpath)) {
+			g_debug ("not yet in db: %s", fullpath);
+			break;
+		}
+
+		/* it's there, but it's not up to date */
+		if ((size_t)filestamp >= (size_t)data->_dirstamp)
+			break;
+
+		return MU_OK; /* nope: no need to insert/update! */
+
+	} while (0);
+
 		
-	if (!data->_reindex) 
-		if ((size_t)filestamp <= (size_t)data->_dirstamp)
-			return MU_OK;
-	
 	msg = mu_msg_gmime_new (fullpath);
 	if (!msg) {
 		g_warning ("%s: failed to create mu_msg for %s",

src/mu-store-xapian.cc

@@ -300,8 +300,10 @@ mu_store_xapian_remove (MuStoreXapian *store, const char* msgpath)
 		g_debug ("deleting %s", msgpath);
 		
 		++store->_processed;
-		_commit_transaction_if (store,
-					store->_processed % store->_trx_size == 0);
+
+		/* do we need to commit now? */
+		bool commit_now = store->_processed % store->_trx_size == 0;
+		_commit_transaction_if (store, commit_now);
 
 		return MU_OK; 
 		
@@ -309,6 +311,21 @@ mu_store_xapian_remove (MuStoreXapian *store, const char* msgpath)
 	
 }
 
+gboolean
+mu_store_contains_message (MuStoreXapian *store, const char* path)
+{
+	g_return_val_if_fail (store, NULL);
+	g_return_val_if_fail (path, NULL);
+	
+	try {
+		const std::string uid (_get_message_uid(path));
+		return store->_db->term_exists (uid) ? TRUE: FALSE;
+		
+	} MU_XAPIAN_CATCH_BLOCK_RETURN (FALSE);
+}
+
+
+
 time_t
 mu_store_xapian_get_timestamp (MuStoreXapian *store, const char* msgpath)
 {
@@ -352,7 +369,8 @@ mu_store_xapian_foreach (MuStoreXapian *self,
 	g_return_val_if_fail (func, MU_ERROR);
 	
 	try {
-		Xapian::Enquire enq (*self->_db);		
+		Xapian::Enquire enq (*self->_db);
+
 		
 		enq.set_query  (Xapian::Query::MatchAll);
 		enq.set_cutoff (0,0);

src/mu-store-xapian.h

@@ -82,6 +82,18 @@ MuResult	  mu_store_xapian_store   (MuStoreXapian *store,
 MuResult          mu_store_xapian_remove (MuStoreXapian *store,
 					  const char* msgpath);
 
+
+/** 
+ * does a certain message exist in the database already?
+ * 
+ * @param store a store
+ * @param path the message path
+ * 
+ * @return 
+ */
+gboolean          mu_store_contains_message (MuStoreXapian *store,
+					     const char* path);
+
 /** 
  * store a timestamp for a directory
  *